New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  init() {
    this._super();
    this.set('prop', 'foo');
    setTimeout(() => {
      Ember.run(() => {
        this.set('prop', 'bar');
        Ember.run.schedule('afterRender', () => {
          this.set('prop', 'baz');
          Ember.run.schedule('actions', () => {
            this.set('prop', 'quiz');
            Ember.run.schedule('afterRender', () => {
              this.set('prop', 'done');
            });
          });
        });
      });
      console.log(document.body.innerText);
    });
  }
});

templates.application.hbs

{{this.prop}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
  }
}